Well, there have been a few issues in work over the past few days… We’ve had a consultant in modifying the SCW on most of our servers, this has gone well on the whole, however, following the modification of the Domain Controllers (outside of working hours, naturally!). Following this change, it was apparent that we could no longer remote manage DHCP, this appeared to be a specific option that had not been selected.

Unfortunately, our consultant decided to make this change to allow remote administration to all Domain Controllers through the day, once the change was made everything failed… And by everything, I mean EVERYTHING! Mail, Citrix, SQL, Terminal Services, SMS, SCOM, the list goes on.

Once the policy was removed, services were restored. Not an enjoyable 20 minutes! But the question is, why did this occur? The only change made was to DHCP remote administration. The only indication to the issue was IPSEC kicking in on the DCs once the policy was applied. More investigation required I think!